'Don't you love a bit of gore?' asks Deborah, Dowager Duchess of
Devonshire, as I stamp away the snow on the doormat of the airy
Derbyshire vicarage that has been her home since she left
Chatsworth four years ago after 54 years in situ. The taxi
driver who ferried me from Chesterfield Station to have lunch with
the Duchess at Edensor, on the edge of the Chatsworth estate, spent
the 20-minute journey regaling me with gruesome tales of local
massacres. When not waxing lyrical about the horror of the Pottery
Cottage murders and the like, he holds forth on his admiration for
Debo Devonshire, the last living Mitford sister. She insists on
coming out into the snow to meet him before she goes to feed her
chickens. She pulls on a pair of gum boots and shrugs a gilet over
her cream cashmere poloneck and dark green kilt before bounding out
along the snowy drive. She is 90 at the end of March and, although
she remains ramrod straight, she must sense my anxiety about the
treacherous ice beneath our feet because she starts to show off.
'Oh isn't slidey,' she says skidding around like a skater. 'You
wouldn't want to slip,' she chirrups hopping from foot to foot.
Eventually her niece-by-marriage, Charlotte Mosley, appears with a
wooden walking stick - of the variety whittled for rambling and
hiking rather than one intended for the infirm. Because, the
Duchess is not infirm. She is old and her sight is misty but, other
than that, I have rarely met a person more in possession of their
faculties. She chatters away to the somewhat star-struck cab
driver. 'I love a bit of gore' she tells him happily.

Actually she loathes a bit of gore and struggles to find
anything at all to watch on television. 'I am what you might call
selective,' she says. 'I can't look at anything sad or violent or
anything with heaving sheets - I hate that - so that rules out most
of telly.' The Mitfords, historically, have not dwelt on the darker
side of life though at times they have lived it. A selection
of 75 years' worth of letters between the six sisters was published
in 2007, and some readers found their resolute lightness of touch a
little grotesque. 'I think we made little of sorrow really,' says
Debo. 'We weren't sloppy-sentimental. It was all rather skated
over. It wasn't the thing to keep belly-aching.' Perhaps a
collection of letters is rather like a photograph album: dedicated
to the good times. 'Deborah Devonshire is not someone to whom one
can say "Joking apart…' wrote Alan Bennett in his introduction to
Home to Roost and Other Peckings the Duchess's most recent
collection of essays. 'Joking is never apart: with her it's of the
essence even of the most serious and indeed saddest moments.'

Debo was the baby of seven - six sisters and a brother. Her
autobiography, coming out in September, will be called Wait For Me,
'Because of my stubby, stumpy legs and all the others running
away.' Her parents, David, 2nd Baron Redesdale and his wife Sydney
always called her Stubby - in Mitford world nicknames stick. Even
the current Duke of Devonshire, Debo's son Peregrine, is known to
everybody as Stoker. Nancy, the oldest of the seven Mitford
siblings, 16 years Debo's senior, always called her Nine because
she declared that to be her mental age. Nancy was the acclaimed
novelist, although Debo's autobiography will be her 12th book
(including a cookbook, various tomes about Chatsworth and the
surrounding countryside and collections of short observational
pieces), which makes her almost as prolific. 'Nancy would have
thought it very, very comical that anything written by the nine
year-old could be taken the least bit seriously,' says Debo who
adored Nancy. 'Then she would have laughed at some of the jokes. I
think she would.'

Nancy was sounds terrifying. Life never went quite right for her
and she was prone to almost bizarre displays of disloyalty and
pique, presumably fuelled by jealousy. After all, Debo, the squit
of the family with a thumb flat from sucking (Nancy once declared
to a tearful young Debo that no one would ever marry her on account
of that deformed thumb) was meant to be marrying a publisher. Her
late husband, Lord Andrew Cavendish, was a younger son when she
married him, and they both fully expected to be poor unless he
could carve out a career for himself working for 'Uncle Harold'
Macmillan who was married to Dorothy Cavendish, Andrew's aunt. Like
the Queen Mother, Debo was looking forward to a life of relative
obscurity- where she could have as many dogs and chickens as she
pleased and no one would tell her not to let them crawl over the
sofa - until her brother-in-law, Billy Hartington was killed by a
sniper's bullet in 1944, four months after his marriage to Kathleen
'Kick' Kennedy, JFK's lively sister. Four years later the
immensely popular Kick died in a plane crash and is buried in the
churchyard at Edensor at the bottom of Debo's garden. On her
headstone is engraved, 'Joy she gave. Joy she has found.'

When the 10th Duke died unexpectedly in 1950, Deborah and Andrew
found themselves the 11th Duke and Duchess of Devonshire with
Chatsworth, Hardwick Hall, Lismore Castle and Bolton Abbey to look
after, not to mention per cent death duties (the old duke had died
14 weeks before tax relief would have kicked in) to tackle if they
were to hold on to them. After Hardwick Hall was donated to the
nation, precious works of art were sold and Andrew negotiated and
juggled endlessly, the debt was finally settled in 1974. Debo
redecorated Chatsworth entirely and with great élan; it had been
leased to a girl's school and was sorely battered. Once she had
added, among other things, 17 new bathrooms, ('Who is my sister
going to wash in all those bathrooms?' asked an acid Nancy) she
entertained extensively and is completely relaxing as a hostess.
'Won't you have cream?' she asks as her cook produces a lime and
chocolate buttermilk pudding to follow the kedgeree (made with her
chickens' eggs) that we have had for lunch. 'My mother used to say
that the English way of entertaining was to light a fire and put
cream into every course.'

In 1977 Debo - controversially - opened her Chatsworth Farm Shop
which paved the way for fancy farm businesses like Daylesford and
Prince Charles's Highgrove Farm shop as well as helping Chatsworth
to wash its face. 'It was against the collar because the estate
office said that we had no knowledge of retailing food and that it
was a complete shot in the dark and it would upset the butchers,'
she remembers. 'It would upset everybody according to them and of
course in the end it didn't upset anybody.' It now turns over
nearly £6 million. 'People have a sort of misapprehension that it
was me that stopped Chatsworth from being sold but that's
absolutely not true. It was entirely Andrew,' she says. 'He was
funny and clever and cross sometimes and marvellous lots of times.'
They had three children - Emma (mother of the model Stella
Tennant), Stoker and Sophia - as well as three babies who died soon
after birth. 'Having babies successfully seems to be the most
difficult thing in the world,' she wrote to Nancy in May 1947. 'I
can't think how some people manage to pull it off every time.' She
still doesn't talk about her sorrows, unable to see the point of
dwelling. 'Grief. It is part of life,' she says. 'The disaster of
someone dying was talked about for a bit and the person was mourned
but you didn't go on about it and take pills and have to be
counselled. Money and illness and sex were not talked about in
those days and they are the only things people talk about these
days, aren't they?'

The late Duke was also, at times, rather over-shadowed by his
magical Mitford wife, despite Debo's distaste - initial, she
has got used to it now - for the spotlight. It was undoubtedly a
successful marriage (lasting for 63 years until Andrew died in
2004) but he nonetheless took advantage of the freedom his long
stays at their house in Mayfair afforded him, while she was much
admired. She sat for Lucian Freud who remains a great friend,
and the priapic but charismatic Jack Kennedy was a devotee. 'Lucian
Freud came for the weekend,' wrote Debo to Diana in August 1957.
'He seems very nice & not at all wicked but I'm always wrong
about that kind of thing. He's mad on tennis, rather
unexpected.'

The Duke admitted he could feel a bit jealous of the Mitford
mania: "Did you see the musical about them?' he asked, 'I called it
La Triviata." Debo has always rather cultivated the myth
of her own stupidity, selling herself as deeply unlettered and
ignorant and consistently declaring her ennui when faced with a
book. It seems to me that where most people pretend to have read
the books they haven't, Debo has tended to err on the side of
pretending not to have read the books that she has. 'There
may be a substratum of truth in that,' she admits. 'That was to get
out of talking about them for hours.'

She has always stringently avoided talking about or declaring
any interest in politics even though Andrew unsuccessfully
contested Chesterfield for the Conservatives in 1945 and again in
1950. This natural lack of interest was also a useful one as most
of her sisters had an unlikely predeliction for the more vigorous
end of mid-20th-century politics. Pamela Mitford, the second-oldest
sister, quietly married a physicist called Derek Jackson (15
year-old Debo had a crush on Derek and fainted when she heard the
news. 'I have always been in love with somebody or something,' she
says), but she was the exception.

At 18 Jessica, the second-youngest sister, and the red sheep of
the family, ran off to Spain with Esmond Romilly to fight for the
communist cause. Romilly was a rare beast in that he was one of the
terribly few people who Debo has truly disliked. 'He was just so
awful to our parents,' she says. 'Disrespectful would be putting it
mildly. He was incredibly rude and unpleasant in every possible
way.' When Jessica absconded, Debo felt rather abandoned, living,
as she was, in a tiny cottage in the Cotswold village of Swinbrook
with her mild-mannered mother and her extremely irascible father,
who was immortalised by Nancy as Uncle Matthew in The Pursuit of
Love. 'He was just so funny,' says Debo. 'It was the turn of phrase
and the way he really muddled people by the fact that they didn't
know if he was serious or not. He started everything with, "Have a
gasper,' and gave them one of the cheapest Wills cigarettes. He
could be frightening - you did as far as you dared and then he
turned and roared at you. Actually, I was immune because I was the
last and I happened to be the favourite.'

And while the others were desperate to escape the country, Debo
has always been a true land girl with her chickens and dogs and
horses and guinea pigs and shooting and hunting and gardening and
estate management and all that wholesome stuff that served her well
as a chatelaine, although she once lamented that Chatsworth's 297
rooms (that figure varies according to source) made puppy training
exceedingly tricky.

Debo thinks her father must have longed for male company
surrounded as he was by women. Her only brother Tom, was away at
Eton and was later killed in Burma in 1945. The girls were all
schooled by a governess at home because Lord Redesdale disapproved
of education for women and refused to send his daughters to school
because he though hockey would make their ankles fat.

Unity, the third sister, notoriously became obsessed with Nazism
and fell in love with Adolf Hitler. Debo had tea with him once but
it was all conducted in German and she says that he 'didn't make a
great impression.' Debo's big crush is Elvis and plans to include
the section of his picket fence that she procured from Graceland
(it had to be replaced when he became really famous because, she
says, 'it wasn't man enough for the job') in the exhibition of her
life that will take place at Chatsworth from mid-March. She becomes
almost po -faced with passion when talking about Elvis. 'First of
all, when he was young he was astonishingly beautiful, secondly
he's got the best voice of any of those singers by far and away and
thirdly his timing is so wonderful. He's absolutely precise and
there's that self-deprecating charm so you feel that you just love
him because he's so self-conscious about being famous.' Lack of
self-congratulation was essential to the Mitford
philosophy.'Self-pity and self-esteem, which are now the key things
in schools, were not allowed,' she says. 'Self esteem? Nanny used
to say, 'Who's going to look at you?' Nanny rather forgot herself
and said that to Diana on her wedding day. 'And she looked so
beautiful,' recalls Debo with just a touch of wistfulness. 'She was
always beautiful; she never had an off day.'

On 3rd September 1939, the day that England a France declared
war on Germany, Unity, unable to reconcile herself with the
conflict between her homeland and the Fatherland, took herself off
to the English Garden in Munich and shot herself in the head. The
bullet failed to kill her but lodged itself in her brain inflicting
irreversible brain damage. Hitler arranged for Unity to be
transported to Switzerland and Debo accompanied her mother to
collect the invalid. 'She was not the person we knew,' says Debo.
'I don't know if you have come across someone who has had a major
stroke and has a completely changed personality, but she was like
that and it was so sad.' Unity became a very bombastic creature who
replaced her political fervour with religious zeal.

Eventually the Redesdales separated. Their marriage was already
under strain from political disagreements (he was violently
anti-German, she wasn't) and Lord Redesdale eventually departed for
Inch Kenneth, a tiny island in the Inner Hebrides, taking the
parlour-maid Margaret Wright with him. 'Unity was a terribly
destructive influence in a way,' says Debo. 'It was like having a
new child in the house and it was quite hard because we lived in a
very small cottage and we were all hug-a-mug.' In Mitford style,
the Redesdales remained firm penpals until he died in 1958, 10
years after Unity's death aged 33, from meningitis.

Diana, Debo's favourite sister, left her first husband, Bryan
Guinness, for the fascist leader Sir Oswald Mosley, and was
imprisoned in Holloway from 1940 until 1943. Nancy informed on
Diana to the Foreign Office, calling her 'an extremely dangerous
person.' She later admitted that this was, 'not very sisterly
behaviour' but did it again in protest against her sister's release
from prison, a betrayal that Diana mercifully never discovered.
Although Nancy was sharp and elegant, Diana was the staggering
beauty, and it may have fanned the flames when Diana, who had two
sons from her first marriage, gave birth to two Mosley sons
(Formula 1's Max, and Alexander, who died four years ago) within
weeks of Nancy's two miscarriages.

Nancy, with her naturally satirical mind, could not observe
Unity's naïve passion and Diana's commitment to the fascist cause
(so at odds with her gentle, empathetic character) without
immortalising it as best she knew how. Wigs On The Green
is her most obscure novel largely because it has been out of print
for nearly 75 years and is only now about to be reprinted with a
forward by Charlotte Mosley. First published in 1935, it satirised
Unity's blind gusto and fascism in general. A character called
Eugenia Malmains - notably large in stature like Unity - dashes
around the county banging her drum for the Union Jackshirts and
trying to stop her nanny and granny (TPOF which stands for The Poor
Old Female) from sabotaging her grand political plan.

Both Diana and Unity took a very dim view, furious with Nancy
for mocking Mosley's Blackshirts, and the novel caused a rift
between the sisters that took years to heal. Apart from just having
a go, Nancy was scrabbling - or scribbling - about, trying to make
a living. This was ten years before the publication of The
Pursuit of Love, the novel that would make her a sta, and she,
like the rest of her sisters prior to their marriages, had no
money. It can't have helped that her own romantic life was fairly
dismal. In 1933, after a dead-end romance with Hamish
St.Clair-Eskine who was gay, she married Peter Rodd who was
handsome, poor, lazy and amusing. 'He was hopeless as a husband,'
says Debo. 'He never held down a job so he never earned any money
and he was a sort of tramp really, by nature. Very clever. He knew
everything, really everything, and he used to rather rattle on
about it. But I was rather fond of him and he was awfully
nice-looking. He wasn't very nice to Nancy and used to bring back
drunken friends from the pub - such a nuisance.' Peter appears in
Wigs On The Green in the form of Jasper, a witty waster and
parasite who blackmails and cajoles his way through life. He and
Nancy separated in 1939 but didn't divorce until 1958, by which
time Nancy had long been in love with Colonel Gaston Palewski
(Charles de Gaulle's Chief of Staff), with whom she had an affair
during the Second World War. She moved to Paris to be near him but
the relationship was largely one-sided. 'They were never an item
but he was very fond of her,' says Debo. When the Colonel married a
French aristocrat in 1969, Nancy was heartbroken and was soon
diagnosed with cancer of the liver and then the spine. 'Her illness
was a nightmare,' says Debo. 'Four years of intermittent agony
then, 'oh, I'm cured,' and the next day back came the pain.' Nancy
died in 1973 and the Colonel was with her on the day she died. She
is buried at Swinbrook next to her parents, her sisters and a
memorial commemorating her brother Tom whose body was never
recovered from Burma.

Debo's eyesight is too poor for reading nowadays although she
plans to get someone to read her Wigs On The Green to
remind herself of all Nancy's 'marvellous jokes.' She can still
write - 'although I can't read what I've written which sounds very
upside down but happens to be true' - and still answers all her fan
mail by hand. People have suggested a one-size-fits-all typed
template that she might top and tail but she won't hear of it.
Nancy, on the other hand, copied Evelyn Waugh's example and used to
send back a postcard with, 'Nancy Mitford is unable to do what you
ask' printed on it.

Debo misses her sisters but says that with advanced age has
arrived a certain numbing of emotion. 'Things went rather over my
mother's head and I must say I notice they do over mine now.' A
Mitford to the core, rather than dissolving herself in the past,
she prefers to berate her chickens for not laying enough, put on
all her jewels at once to play The Oldest Miss World In The World
(this was a few years ago) for the Women's Institute, or host a
floral fanfare in the local church complete with a cardboard
cut-out of Elvis (this was a few weeks ago) and Alan Bennett making
a star turn. She brought an almost American vigour to the job of
being a Duchess. 'Somebody asked me what it's like to be a duchess.
Well, it's absolutely no different to anything else. I've been one
for so long now that I can't remember what it was like before.' And
neither can anyone else.